Mammoth (and to be honest, Kelsae, Globo and several others) aren't really monster onions, they're like Unwins Exhibition, a very large onion for the beauty-pageant side of vegetable shows..... and size does count there, if you can put up five identically sized onions of good shape that weigh 2lbs a piece then you will beat the guy with equally good onions that weigh 8 ounces each..... but if you want a monster then it's special seed strains and the easiest one to get hold of (and the starting point for just about all the rest) is Aislae.......
